1. Field of the Invention
The present invention relates to a transfer control device, a transfer control method, a transfer unit and a disc unit for unloading a disc article to be transferred from a casing through an opening.
2. Description of Related Art
Heretofore, as a disc article to be transferred, a disc unit has been known that reads information recorded on a disc recording medium and records information on a disc recording medium. As such a disc unit, there is known a so-called slot-in type in which a transfer unit is provided for loading a disc recording medium into a casing and unloading the disc recording medium from the casing through a slit-shaped opening disposed at a front side. The slot-in type disc unit detects the disc recording medium by means of a switch or a sensor in order to control the drive of the transfer unit based on a detection status (see Patent Document 1: Japanese Patent Laid-Open publication No. 2001-56994 and Patent Document 2: Japanese Patent Laid-Open publication No. 2003-208744, for example).
A disc unit disclosed in the Patent Document 1 stops the drive of a roller for pulling and ejecting a disc when detecting that the large-diameter disc passes to be ejected by means of a disc passage detecting switch. When the disc passage detecting switch detects that a small-diameter disc passes to be ejected, the disc unit drives the roller for a predefined period of time to eject the disc for a distance A before stopping driving. Thus, the disc unit can stop the disc with different diameter (large or small) in a state that the disc center hole is ejected out of the disc unit body.
In a disc unit disclosed in the Patent Document 2, an optical detector is provided at a position where the detector does not face a small-diameter disc when a clamp mechanism for clamping discs clamps the small-diameter disc but faces a large-diameter disc when the clamp mechanism clamps the large-diameter disc, and the detector faces neither of the discs (small or large) when the discs are at each predefined ejection position, and the detector is near the position where the peripheries of the both discs intersect. When a disc is inserted, the detector detects the peripheral edge of the disc, thereby actuating a transfer roller to load the disc. When the disc is ejected, the transfer roller is arranged to be stopped if the detector cannot detect the disc.
In the above-described conventional arrangements disclosed in the Patent Documents 1 and 2, when unloading the disc recording medium by the transfer unit, the center of the disc recording medium may veer off the moving path of the disc recording medium passing through the center of the opening. In this case, the detection status of the disc recording medium by the switch or sensor changes as compared with the usual case where the center of the disc recording medium moves along the moving path. Accordingly, the disc recording medium may not be stopped at a normal predefined position, resulting in that, for instance, the disc recording medium may be overly unloaded to be dropped from the opening or that the disc recording medium may be stopped before the predefined position, so that the disc recording medium cannot be appropriately removed, which are disadvantageous.